(1) Vents shall be required for casings, tunnels and galleries enclosing carriers of fuel where required by C.F.R. 49, Part 192, Minimum Federal Safety Standards. Vent standpipes shall be located and constructed so as not to interfere with maintenance of the highway nor to be concealed by vegetation; preferably they should stand by a fence or on the right of way line.

(2) Drains shall be required for casings, tunnels, or galleries enclosing carriers of liquid, liquefied gas or heavy gas. Drains may outfall into the roadway ditch or natural water course at locations approved by the department. The outfall shall not be used as a wasteway for purging the carrier unless specifically authorized by the department.

(3) Marker location and emergency information shall be conspicuously marked for all pipelines, using color if necessary to contrast with the environment. They should be provided at one end of a normal crossing, at both ends of an oblique crossing and at five hundred foot intervals along a longitudinal installation. Markers shall include pipeline identification and station; owner of the pipeline; and telephone number or other means of contact with local office. Markers may also include depth of cover, size, pressure and contents of carrier, and potential of ducted wires and cables.

(4) Manholes shall not be located in the pavement or shoulders of any access controlled highway. Manholes should be designed and located in such a manner that will cause the least interference to other utilities and future highway expansion.

(5) Automatic shut-off valves shall be installed in line at or near ends of structures, near unusual hazards, unless the hazardous segments can be isolated by other sectionalizing devices within a reasonable distance.

(6) Above-ground appurtenances shall be located to comply with the control zone guidelines.